The Biostatistics and Data Management Core provides administrative, data management, and biostatistical expertise for clinical and basic science research projects in the bone marrow transplant research programs. This core resource provides a high level of technical expertise to support a broad array of research needs and activities. These include biostatistical consultation for design, monitoring, and analysis of clinical and laboratory studies, data management support for clinical trials, and database development/integration with other vital resources in the Oncology Center. The Biostatistics and Data Management Core contains personnel, equipment, and computer software for design of clinical and laboratory studies (e.g., estimation of sample size and study duration), data capture and management (e.g., relational database system), and data analysis (e.g., statistical analysis and graphics packages). We anticipate that current research proposals will continue to make significant demands on the biostatistics and data management core. The core can meet these demands through a combination of improved procedures, computer based tools, and adequate staffing.